According to that link you posted, it states billing in that format is more than twice as expensive. If you have a possibility of moving to that billing format, I would think you would opt out if you could.

It states that it's more than twice the cost of average-based billing. Guess what billing method nobody sells around here.

The available alternative to 95th percentile billing is fixed rate, which is essentially 100th percentile. With that model, you either go big to handle your peak times or you go small to be affordable, and your users feel the congestion. At least 95th percentile billing gives some relief compared to the flat model, which is where many of us are at now.

Suppose that linked RRD graph was yours and typical. What are your choices?

clarknova is right. The billing model is imposed by the seller of bandwidth here, it's not a choice we can elect to take or not. All of our "wholesale" transport is priced this way. I have only one question, tho… Wouldn't we need to input the "window" over which the 95th percentile is calculated? In order to match our billing?

Seems it doesn't like something about the option string. I'm not familiar enough with RRD to know for sure why or how to fix it.
As a quick fix I edited /usr/local/www/status_rrd_graph_img.php to make 'out' the same as 'in' (removing ,$multiplier,*) to end up with:

I'm guessing that will break the scaling of the 95th line but hey it works for now at least. :D
Bill
Ps. Great work to everyone involved working on pfsense! In process of migrating from m0n0wall (need multiwan mostly) and aside from a few issues, (such as this graphing thing and a PPPoE/interface issue I need to report when I get time), it has been working great.